1. Field of the Invention
The present invention relates to a process cartridge and an image forming apparatus to which such a process cartridge can be mounted. The image forming apparatus may be, for example, an electrophotographic copying machine, a laser beam printer, an LED printer, a facsimile machine or the like.
2. Related Background Art
In the past, various image forming apparatuses using laser light have been put to practical use. In such an image forming apparatus using laser light, a laser light path blocking means is openably arranged in a laser light path to block the laser light path at need. Particularly, in an image forming apparatus having a removable process cartridge including a photosensitive member and at least one process means acting on the photosensitive member, when the cartridge is dismounted from the image forming apparatus, since it is feared that the laser light path is exposed to the outside of the apparatus, thereby leaking the laser light out of the apparatus, such blocking means is effective.
By the way, in order to shift such blocking means, a projection is formed on a frame of the cartridge so that, when the cartridge is mounted to the image forming apparatus, the projection is engaged by the blocking means, thereby shifting blocking means to open the laser light path (refer to the Japanese Patent Application Laid-open No. 59-151170).
On the other hand, the process cartridge is provided with a gear as a driving force receiving means for receiving a driving force from the image forming apparatus when the process cartridge is mounted to the image forming apparatus. When the process cartridge is mounted to the image forming apparatus, the gear of the process cartridge is engaged by a gear of the image forming apparatus, thereby transmitting the driving force from the apparatus to the cartridge (refer to U.S. Pat. No. 4,829,335).
With the arrangement mentioned above, when the process cartridge is mounted to the image forming apparatus, it is desirable to correctly and smoothly engage such gears with each other.
Further, in general, as shown in FIG. 33, the process cartridge 141 is packed in a packing material such as bag 140 made of aluminium deposited polyethylene film, and the cartridge with the bag is enclosed by buffer members 142 made of styrol foam or molded pulp and is stored in a box 143 made of corrugated cardboard. However, when the cartridge is provided with the projection (protruded rib) 144 (FIG. 34), it is feared that the packing material is torn by the projection. Thus, it is desirable to provide a process cartridge which does not tear such packing material.